libMesh::OFFIO Class Reference

This class is responsible for reading an unstructured, triangulated surface in the standard OFF OOGL format. More...

#include <off_io.h>

Inheritance diagram for libMesh::OFFIO:

Public Member Functions
	OFFIO (MeshBase &)
	Constructor.
virtual void	read (const std::string &name) override
	Reads in an OFF OOGL data file based on the string you pass it.
bool	is_parallel_format () const
	Returns true iff this mesh file format and input class are parallelized, so that all processors can read their share of the data at once.

Protected Member Functions
MeshBase &	mesh ()
void	set_n_partitions (unsigned int n_parts)
	Sets the number of partitions in the mesh.
void	skip_comment_lines (std::istream &in, const char comment_start)
	Reads input from in, skipping all the lines that start with the character comment_start.

Protected Attributes
std::vector< bool >	elems_of_dimension
	A vector of bools describing what dimension elements have been encountered when reading a mesh.

Private Member Functions
void	read_stream (std::istream &in)
	Implementation of the read() function.

Private Attributes
MeshBase *	_obj
	A pointer to a non-const object object.
const bool	_is_parallel_format
	Flag specifying whether this format is parallel-capable.

Detailed Description

This class is responsible for reading an unstructured, triangulated surface in the standard OFF OOGL format.

Author

John W. Peterson

Date

2004

Reads OOF OOGL triangulated surface files.

Definition at line 39 of file off_io.h.

Constructor & Destructor Documentation

OFFIO()

libMesh::OFFIO::OFFIO ( MeshBase &  mesh_in )

inlineexplicit

Constructor.

Takes a non-const Mesh reference which it will fill up with elements.

Definition at line 68 of file off_io.h.

                                :
  MeshInput<MeshBase> (mesh_in)
{}

Member Function Documentation

is_parallel_format()

bool libMesh::MeshInput< MeshBase >::is_parallel_format ( ) const

inlineinherited

Returns true iff this mesh file format and input class are parallelized, so that all processors can read their share of the data at once.

Definition at line 87 of file mesh_input.h.

{ return this->_is_parallel_format; }

mesh()

MeshBase & libMesh::MeshInput< MeshBase >::mesh ( )

inlineprotectedinherited

Returns

The object as a writable reference.

Definition at line 94 of file mesh_input.h.

{
  libmesh_error_msg_if(_obj == nullptr, "ERROR: _obj should not be nullptr!");
  return *_obj;
}

read()

void libMesh::OFFIO::read ( const std::string &  name )

overridevirtual

Reads in an OFF OOGL data file based on the string you pass it.

Implements libMesh::MeshInput< MeshBase >.

Definition at line 35 of file off_io.C.

{
  std::ifstream in (name.c_str());
 
  read_stream(in);
}

References read_stream().

Referenced by libMesh::NameBasedIO::read().

read_stream()

void libMesh::OFFIO::read_stream ( std::istream &  in )

private

Implementation of the read() function.

This function is called by the public interface function and implements reading the file.

Definition at line 44 of file off_io.C.

{
  // This is a serial-only process for now;
  // the Mesh should be read on processor 0 and
  // broadcast later
  libmesh_assert_equal_to (this->mesh().processor_id(), 0);
 
  // Get a reference to the mesh
  MeshBase & the_mesh = MeshInput<MeshBase>::mesh();
 
  // Clear any existing mesh data
  the_mesh.clear();
 
  // Check the input buffer
  libmesh_assert (in.good());
 
  unsigned int nn, ne, nf;
 
  std::string label;
 
  // Read the first string.  It should say "OFF"
  in >> label;
 
  libmesh_assert_equal_to (label, "OFF");
 
  // read the number of nodes, faces, and edges
  in >> nn >> nf >> ne;
 
 
  Real x=0., y=0., z=0.;
 
  // Read the nodes
  for (unsigned int n=0; n<nn; n++)
    {
      libmesh_assert (in.good());
 
      in >> x
         >> y
         >> z;
 
      the_mesh.add_point ( Point(x,y,z), n );
    }
 
  unsigned int nv, nid;
 
  // Read the elements
  for (unsigned int e=0; e<nf; e++)
    {
      libmesh_assert (in.good());
 
      // The number of vertices in the element
      in >> nv;
 
      libmesh_assert(nv == 2 || nv == 3);
      if (e == 0)
        {
          the_mesh.set_mesh_dimension(cast_int<unsigned char>(nv-1));
          if (nv == 3)
            {
#if LIBMESH_DIM < 2
              libmesh_error_msg("Cannot open dimension 2 mesh file when configured without 2D support.");
#endif
            }
        }
 
      std::unique_ptr<Elem> elem;
      switch (nv)
        {
        case 2:
          elem = Elem::build(EDGE2);
          break;
 
        case 3:
          elem = Elem::build(TRI3);
          break;
 
        default:
          libmesh_error_msg("Unsupported nv = " << nv);
        }
 
      elem->set_id(e);
 
      for (unsigned int i=0; i<nv; i++)
        {
          in >> nid;
          elem->set_node(i, the_mesh.node_ptr(nid));
        }
 
      the_mesh.add_elem(std::move(elem));
    }
}

References libMesh::MeshBase::add_elem(), libMesh::MeshBase::add_point(), libMesh::Elem::build(), libMesh::MeshBase::clear(), libMesh::EDGE2, libMesh::libmesh_assert(), libMesh::MeshInput< MT >::mesh(), libMesh::MeshInput< MeshBase >::mesh(), libMesh::MeshBase::node_ptr(), libMesh::Real, libMesh::MeshBase::set_mesh_dimension(), and libMesh::TRI3.

Referenced by read().

set_n_partitions()

void libMesh::MeshInput< MeshBase >::set_n_partitions ( unsigned int  n_parts )

inlineprotectedinherited

Sets the number of partitions in the mesh.

Typically this gets done by the partitioner, but some parallel file formats begin "pre-partitioned".

Definition at line 101 of file mesh_input.h.

{ this->mesh().set_n_partitions() = n_parts; }

skip_comment_lines()

void libMesh::MeshInput< MeshBase >::skip_comment_lines ( std::istream &  in, const char  comment_start  )

protectedinherited

Reads input from in, skipping all the lines that start with the character comment_start.

Definition at line 113 of file mesh_input.h.

{
  char c, line[256];
 
  while (in.get(c), c==comment_start)
    in.getline (line, 255);
 
  // put back first character of
  // first non-comment line
  in.putback (c);
}

Member Data Documentation

_is_parallel_format

const bool libMesh::MeshInput< MeshBase >::_is_parallel_format

privateinherited

Flag specifying whether this format is parallel-capable.

If this is false (default) I/O is only permitted when the mesh has been serialized.

Definition at line 130 of file mesh_input.h.

_obj

MeshBase * libMesh::MeshInput< MeshBase >::_obj

privateinherited

A pointer to a non-const object object.

This allows us to read the object from file.

Definition at line 123 of file mesh_input.h.

elems_of_dimension

std::vector<bool> libMesh::MeshInput< MeshBase >::elems_of_dimension

protectedinherited

A vector of bools describing what dimension elements have been encountered when reading a mesh.

Definition at line 107 of file mesh_input.h.

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The documentation for this class was generated from the following files:

• include/mesh/off_io.h
• src/mesh/off_io.C